The «golden standard» for evaluating tissue changes is a biopsy followed by pathomorphological examination. Guided trephine biopsy of jaw bones is one of the existing methods of obtaining biopsy material, which we proposed earlier. Objective. To assess clinical efficacy of guided trephine biopsy of jaw bones. Materials and methods. A number of patients equal 62 were included in the study. They were divided into two groups of 31 subjects using «sealed envelopes» method: the 1st group had a guided trephine biopsy using a manual trephine needle for trephine biopsy; the 2nd group — guided trephine biopsy using machine trephines. The obtained biopsy material was sent for pathomorphological ex-amination. The evaluation of the postoperative period’s clinical course was conducted on the 1st, 3rd and 7th days after the biopsy. Results. Success rate of guided trephine biopsy in the first group of patients was 52%, in the second — 71%. The number of oc-curred complications in the first group was 48.39%, in the second — 64.52%. The clinical course of the postoperative period was not fundamentally different in both groups. Conclusion. Thus, it has been determined according to the obtained study results that the use of a new method of guided trephine biopsy of jaw bones can be effective both with the use of manual trephine and machine. In addition, machine trephine can be con-sidered more universal and more effective than manual. © 2024, Media Sphera Publishing Group. All rights reserved.